Renesas R4F20235NFD#U0

Overview

R4F20235NFD#U0 from Renesas Electronics is a 16-bit single-chip microcontroller in the H8S/Tiny series, designed for embedded control in resource-constrained industrial and consumer systems. It features 128 KB on-chip Flash memory, 8 KB RAM, a 20 MHz max CPU clock, 57 I/O pins, and integrated peripherals including 3-channel 16-bit timers, UART, I²C, and 10-bit ADC with 8 input channels.

For engineers reviewing the R4F20235NFD#U0 datasheet, R4F20235NFD#U0 pinout, R4F20235NFD#U0 application, or R4F20235NFD#U0 equivalent, key selection criteria include Flash endurance (10,000 write/erase cycles), operating voltage range (2.7–5.5 V), -40°C to +85°C industrial temperature grade, and support for in-circuit debugging via on-chip FINE interface.

Technical Context

The R4F20235NFD#U0 implements the H8S/2000 CPU core with 24-bit address space, supporting advanced mode operation and 16-bit data paths. Its system architecture integrates a Clock Pulse Generator (CPG) with internal oscillator, PLL, and multiple clock sources, enabling flexible power management via three low-power modes (HALT, STOP, and WAIT).

Peripheral integration includes a Data Transfer Controller (DTC) for autonomous memory transfers, an Event Link Controller (ELC) for hardware-triggered peripheral chaining, and a Peripheral I/O Mapping Controller (PMC) that allows dynamic remapping of peripheral functions to GPIO pins - all coordinated under a centralized interrupt controller with 128 vector entries and priority-based nesting.

Key Specifications

Pinout & Package

R4F20235NFD#U0 is housed in a 64-pin LQFP package (10 mm × 10 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments are defined per Section 1.4 of the H8S/20103–20235 Hardware User's Manual (Rev. 3.00, Sep 2010), and include dedicated reset, clock input, debug (FINE), and power supply pins.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microcontroller applications.

Compared with R5F21235NFD#U0 and HD64F20235FV, the R4F20235NFD#U0 provides optimal balance of legacy code compatibility, compact LQFP-64 footprint, and proven industrial qualification - making it the preferred choice for cost-sensitive, volume-manufactured control modules where toolchain continuity and debug simplicity are critical.

Availability

R4F20235NFD#U0 is available at Aetrix Electronics and suitable for industrial motor control, smart sensor nodes, home appliance UI panels, and programmable logic relays requiring stable component supply across multi-year production cycles.

Supply support for R4F20235NFD#U0 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics Corporation is a global semiconductor leader specializing in microcontrollers, analog, power, and SoC solutions for automotive, industrial, and IoT markets.

The H8S/Tiny series - including the R4F20235NFD#U0 - was engineered for cost-effective, high-reliability embedded control in industrial equipment and consumer appliances where deterministic real-time performance and long-term supply stability are essential.

FAQ

What is the maximum operating frequency of the R4F20235NFD#U0?

The R4F20235NFD#U0 supports a maximum CPU clock frequency of 20 MHz when powered within its specified 2.7–5.5 V operating voltage range. This frequency is achievable using either the internal high-speed oscillator (with PLL) or an external crystal up to 20 MHz. The actual sustained performance depends on wait-state configuration for Flash access and peripheral clock dividers, as detailed in Section 5.2 of the Hardware User's Manual.

Does the R4F20235NFD#U0 support in-system programming (ISP)?

Yes, the R4F20235NFD#U0 supports in-system programming via its on-chip FINE debug interface, enabling full Flash memory read/write/erase operations without removing the device from the target board. This capability is used by Renesas' Flash development toolkit (FDT) and compatible third-party programmers. ISP requires only two dedicated pins (EXC/EXD) and operates at standard logic levels, eliminating the need for high-voltage programming signals.

What are the power supply requirements for reliable operation of the R4F20235NFD#U0?

The R4F20235NFD#U0 requires a clean, regulated supply between 2.7 V and 5.5 V on VCC pins, with separate VSS connections for analog and digital grounds. Decoupling capacitors (100 nF ceramic + 10 μF tantalum) must be placed within 5 mm of each VCC–VSS pair. The device incorporates a Low-Voltage Detection (LVD) circuit with user-selectable thresholds (2.7 V, 3.3 V, 4.0 V) to generate reset or interrupt before supply collapse compromises Flash integrity or logic states.

How many analog-to-digital converter (ADC) input channels does the R4F20235NFD#U0 provide?

The R4F20235NFD#U0 integrates a 10-bit successive-approximation ADC with eight dedicated analog input channels (AD0–AD7), each capable of single-ended or differential measurement. Conversion time is fixed at 1.2 μs per sample, and the ADC supports software-triggered, timer-triggered, or external-event-triggered acquisition. An internal 2.5 V reference is available, or users may select external reference voltage applied to the AVREF pin.

Is the R4F20235NFD#U0 pin-compatible with other devices in the H8S/20235 group?

Yes, the R4F20235NFD#U0 shares identical pinout and electrical characteristics with all members of the H8S/20235 group, including R4F20235NFD#W1 and R4F20235NFD#U5. These variants differ only in packaging (e.g., tape-and-reel vs. tray) and screening (industrial vs. extended temperature), not in silicon functionality or pin assignment. Full compatibility is confirmed in Section 1.4.1 ("Pin Functions") of the H8S/20103–20235 Hardware User's Manual.